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Mangroves among the most carbon-rich forest in the tropics

Authors:
  • Washington Department of Natural Resources & University of Washington
  • Oregon State University and Illhaee Sciences International
  • Center for International Forestry Research Bogor Indonesia & Department of Geophysics and Meteorology IPB University Bogor
LETTERS
PUBLISHED ONLINE: 3 APRIL 2011 | DOI: 10.1038/NGEO1123
Mangroves among the most carbon-rich forests in
the tropics
Daniel C. Donato
1
*
, J. Boone Kauffman
2
, Daniel Murdiyarso
3
, Sofyan Kurnianto
3
, Melanie Stidham
4
and Markku Kanninen
5
Mangrove forests occur along ocean coastlines throughout the
tropics, and support numerous ecosystem services, including
fisheries production and nutrient cycling. However, the areal
extent of mangrove forests has declined by 30–50% over the
past half century as a result of coastal development, aqua-
culture expansion and over-harvesting
1–4
. Carbon emissions
resulting from mangrove loss are uncertain, owing in part to
a lack of broad-scale data on the amount of carbon stored
in these ecosystems, particularly below ground
5
. Here, we
quantified whole-ecosystem carbon storage by measuring tree
and dead wood biomass, soil carbon content, and soil depth in
25 mangrove forests across a broad area of the Indo-Pacific
region—spanning 30
of latitude and 73
of longitude—where
mangrove area and diversity are greatest
4,6
. These data indi-
cate that mangroves are among the most carbon-rich forests
in the tropics, containing on average 1,023 Mg carbon per
hectare. Organic-rich soils ranged from 0.5 m to more than 3 m
in depth and accounted for 49–98% of carbon storage in these
systems. Combining our data with other published information,
we estimate that mangrove deforestation generates emissions
of 0.02–0.12 Pg carbon per year—as much as around 10% of
emissions from deforestation globally, despite accounting for
just 0.7% of tropical forest area
6,7
.
Deforestation and land-use change currently account for 8–20%
of global anthropogenic carbon dioxide (CO
2
) emissions, second
only to fossil fuel combustion
7,8
. Recent international climate
agreements highlight Reduced Emissions from Deforestation and
Degradation (REDD+) as a key and relatively cost-effective option
for mitigating climate change; the strategy aims to maintain
terrestrial carbon (C) stores through financial incentives for forest
conservation (for example, carbon credits). REDD+ and similar
programs require rigorous monitoring of C pools and emissions
8,9
,
underscoring the importance of robust C storage estimates for
various forest types, particularly those with a combination of high
C density and widespread land-use change
10
.
Tropical wetland forests (for example, peatlands) contain
organic soils up to several metres deep and are among the largest
organic C reserves in the terrestrial biosphere
11–13
. Peatlands’
disproportionate importance in the link between land use and
climate change has received significant attention since 1997, when
peat fires associated with land clearing in Indonesia increased
atmospheric CO
2
enrichment by 13–40% over global annual
fossil fuel emissions
11
. This importance has prompted calls to
specifically address tropical peatlands in international climate
change mitigation strategies
7,13
.
1
USDA Forest Service, Pacific Southwest Research Station, 60 Nowelo St., Hilo, Hawaii 96720, USA,
2
USDA Forest Service, Northern Research Station, 271
Mast Rd., Durham, New Hampshire 03824, USA,
3
Center for International Forestry Research (CIFOR), PO Box 0113 BOCBD, Bogor 16000, Indonesia,
4
USDA Forest Service, International Programs, 1099 14th street NW, Suite 5500W, Washington, District of Columbia 20005, USA,
5
Viikki Tropical
Resources Institute (VITRI), University of Helsinki, PO Box 27, FIN-00014, Finland. *e-mail: ddonato@wisc.edu.
Overlooked in this discussion are mangrove forests, which occur
along the coasts of most major oceans in 118 countries, adding
30–35% to the global area of tropical wetland forest over peat
swamps alone
4,6,12
. Renowned for an array of ecosystem services,
including fisheries and fibre production, sediment regulation, and
storm/tsunami protection
2–4
, mangroves are nevertheless declining
rapidly as a result of land clearing, aquaculture expansion,
overharvesting, and development
2–6
. A 30–50% areal decline over
the past half-century
1,3
has prompted estimates that mangroves
may functionally disappear in as little as 100 years (refs 1,2). Rapid
twenty-first century sea-level rise has also been cited as a primary
threat to mangroves
14
, which have responded to past sea-level
changes by migrating landward or upward
15
.
Although mangroves are well known for high C assimilation
and flux rates
16–22
, data are surprisingly lacking on whole-ecosystem
carbon storage—the amount which stands to be released with
land-use conversion. Limited components of C storage have been
reported, most notably tree biomass
17,18
, but evidence of deep
organic-rich soils
22–25
suggests these estimates miss the vast majority
of total ecosystem carbon. Mangrove soils consist of a variably
thick, tidally submerged suboxic layer (variously called ‘peat’ or
‘muck’) supporting anaerobic decomposition pathways and having
moderate to high C concentration
16,20,21
. Below-ground C storage
in mangrove soils is difficult to quantify
5,21
and is not a simple
function of measured flux rates—it also integrates thousands of
years of variable deposition, transformation, and erosion dynamics
associated with fluctuating sea levels and episodic disturbances
15
.
No studies so far have integrated the necessary measurements for
total mangrove C storage across broad geographic domains.
In this study we quantified whole-ecosystem C storage in
mangroves across a broad tract of the Indo-Pacific region, the
geographic core of mangrove area ( 40% globally) and diversity
4,6
.
Study sites comprised wide variation in stand composition
and stature (Fig. 1, Supplementary Table S1), spanning 30
of latitude (8
S–22
N), 73
of longitude (90
–163
E), and
including eastern Micronesia (Kosrae); western Micronesia
(Yap and Palau); Sulawesi, Java, Borneo (Indonesia); and the
Sundarbans (Ganges-Brahmaputra Delta, Bangladesh). Along
transects running inland from the seaward edge, we combined
established biometric techniques with soil coring to assess variations
in above- and below-ground C pools as a function of distance
from the seaward edge in two major geomorphic settings:
estuarine/river-delta and oceanic/fringe. Estuarine mangroves
(n = 10) were situated on large alluvial deltas, often with a
protected lagoon; oceanic mangroves (n = 15) were situated in
NATURE GEOSCIENCE | VOL 4 | MAY 2011 | www.nature.com/naturegeoscience 293
© 2011 Macmillan Publishers Limited. All rights reserved.
LETTERS
NATURE GEOSCIENCE DOI: 10.1038/NGEO1123
a
b
Figure 1 | Examples of Indo-Pacific mangroves. The sample included a
broad range of stand stature, composition, and soil depth. a, Exemplary
large-stature, high-density mangrove dominated by Bruguiera, Borneo,
Indonesia (canopy height >15 m, canopy closure >90%, soil depth >3 m).
b, Exemplary small-stature, low-density mangrove dominated by
Rhizophora, Sulawesi, Indonesia (canopy height <4 m, canopy closure
<60%, soil depth 0.35–0.78 m). Both estuarine and oceanic mangroves
can exhibit both conditions (see Supplementary Table S1).
marine-edge settings, often the coasts of islands with fringing
coral reefs. Seaward distance and geomorphic setting may
influence C dynamics through differences in tidal flushing and
relative importance of allochthonous (river sediment) versus
autochthonous (in situ litter and root production) controls on soil
C accumulation
5,16
.
We found that mangroves are among the most C-dense forests
in the tropics (sample-wide mean: 1,023 Mg C ha
1
±88 s.e.m.),
and exceptionally high compared to mean C storage of the
world’s major forest domains (Fig. 2). Estuarine sites contained
a mean of 1,074 Mg C ha
1
(±171 s.e.m.); oceanic sites contained
990 ± 96 Mg C ha
1
. Above-ground C pools were sizeable (mean
159 Mg C ha
1
, maximum 435 Mg C ha
1
), but below-ground
storage in soils dominated, accounting for 71–98% and 49–90%
of total storage in estuarine and oceanic sites, respectively (Figs 2
and 3). Below-ground C storage was positively but weakly
correlated to above-ground storage (R
2
= 0.21 and 0.50 in estuarine
and oceanic sites, respectively). Although soil C pools increased
slightly with distance from the seaward edge in oceanic sites
(because of increasing soil depth), changes in both above- and
Boreal Temperate Tropical
upland
Mangrove
Indo-Pacific
0
200
400
600
800
1,000
1,200
1,400
Ecosystem C storage (Mg ha
¬1
)
Above-ground live + dead
Soils 0¬30 cm depth + roots
Soils below 30 cm depth
Figure 2 | Comparison of mangrove C storage (mean ±95% confidence
interval) with that of major global forest domains. Mean C storage by
domain was derived from ref. 9, including default values for tree, litter, dead
wood, root:shoot ratios, and soils, with the assumption that the top 30 cm
of soil contains 50% of all C residing in soil
9
, except for boreal forests
(25%). Domain means are presented for context; however some forest
types within each contain substantially higher or lower C stores
9,10
. In
general, the top 30 cm of soil C are considered the most vulnerable to
land-use change
9
; however in suboxic peat/muck soils, drainage,
excavation, and oxidation may influence deeper layers
29
.
below-ground C storage over this distance gradient were highly
variable and not statistically significant (Fig. 3).
So far, quantification of below-ground C storage in man-
groves has been impeded by a lack of concurrent data on soil
carbon concentration, bulk density, and depth, and how these
vary spatially
5,21
. We found high C concentration (% dry mass)
throughout the top metre of the soil profile, with a decrease
below 1 m (Fig. 4a). Carbon concentration was lower in es-
tuarine (mean = 7.9%) versus oceanic (mean = 14.6%) sites.
Soil bulk density (BD) did not differ significantly by setting or
distance from the seaward edge (generally 0.35–0.55 g cm
3
),
but did increase with depth (Fig. 4b). Combining C concentra-
tion and BD yielded mean C densities of 0.038 g C cm
3
and
0.061 g C cm
3
in estuarine and oceanic soils, respectively. The
total depth of the peat/muck layer differed between estuarine
and oceanic sites (Fig. 4c) and was the main driver of varia-
tions in below-ground C storage (Fig. 3). Estuarine stands over-
lie deep alluvial sediment deposits, usually exceeding 3 m depth;
oceanic stands contained a distinct organic-rich layer overlying
hard coral sand or rock, with peat/muck thickness increasing
from a mean of 1.2 m (±0.2 s.e.m.) near the seaward edge to
1.7 m (±0.2 s.e.m.) 135 m inland (Fig. 4c). In terms of total
below-ground C storage, the shallower soil depth in oceanic man-
groves was compensated in part by higher soil organic C con-
centration (Fig. 4a,c).
These data indicate that high productivity and C flux rates
in mangroves
16–22
are indeed accompanied by high C storage,
especially below ground. High per-hectare C storage coupled with
a pan-tropical distribution (total area 14 million ha; refs 4,6)
suggests mangroves are a globally important surface C reserve.
Although our sample is not intended to represent all mangrove
types (precluding simple scaling up), some constraints on global
storage can be derived by combining an uncertainty range from
our empirical data (5th to 95th percentile C storage values) with
additional global data on soil C concentration, depth, and standing
biomass
16,17,21,23,24
(see Methods in Supplementary Information).
This approach yields an estimate of 4.0–20 Pg C globally. This
estimate will undoubtedly be refined, but suggests mangroves add
significantly to tropical wetland forest C storage (for example,
tropical peatlands: 82–92 Pg C; ref. 12).
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© 2011 Macmillan Publishers Limited. All rights reserved.
NATURE GEOSCIENCE DOI: 10.1038/NGEO1123
LETTERS
400
200
0
200
400
600
800
1,000
1,200
1,400
Below-ground Above-ground
C storage (Mg ha
¬1
)
400
200
0
200
400
600
800
1,000
1,200
1,400
Below-ground Above-ground
C storage (Mg ha
¬1
)
0 10 35 60 85 110 135
Distance from seaward edge (m)
0 10 35 60 85 110 135
Distance from seaward edge (m)
Estuarine mangroves
Oceanic mangroves
Trees
Down wood
Roots
Soil
ab
Figure 3 | Above- and below-ground C pools in Indo-Pacific mangroves, assessed by distance from the seaward edge. a, Estuarine mangroves situated on
large alluvial deltas. b, Oceanic mangroves situated in marine edge environments—for example, island coasts. Below-ground C comprised 71–98% and
49–90% of ecosystem C in estuarine and oceanic sites, respectively. Overall carbon storage did not vary significantly with distance from the seaward edge
in either setting over the range sampled (P > 0.10 for above-ground, below-ground, and total C storage by functional data analysis (FDA, see Methods);
95% CIs for rates-of-change all overlapped zero and were between 1.2 and 3.9 Mg C ha
1
per metre of distance from edge).
Carbon emissions from land-use change in mangroves are
not well understood. Our data suggest a potential for large
emissions owing to perturbation of large C stocks. The fate of
below-ground pools is particularly understudied, but available
evidence suggests that clearing, drainage, and/or conversion
to aquaculture—aside from affecting vegetation biomass—also
decreases mangrove soil C significantly
16,22,26–28
. In upland forests,
the top 30 cm of soil are generally considered the most susceptible
to land-use change
9
; however in wetland forests, drainage and
oxidation of formerly suboxic soils may also influence deeper
layers
29
. To provide some constraints on estimated emissions,
we used a similar uncertainty propagation technique, combining
our C storage values with other global data
16,17
and applying
a range of assumptions regarding land-use effects on above-
and below-ground pools (see Supplementary Information). This
approach yields a plausible estimate of 112–392 Mg C released
per hectare cleared, depending in large part on how deeply soil
C is affected by different land uses. Coupled with published
ranges of mangrove deforestation rate (1–2%; refs 1,4) and global
area (13.7–15.2 million ha; refs 4,6), this estimate leads to global
emissions on the order of 0.02–0.12 Pg C yr
1
. This rate adds
significantly to oft-cited peatland emissions (0.30 Pg C yr
1
) and
global deforestation emissions (1.2 Pg C yr
1
; ref. 7) despite
accounting only for loss of standing stocks but not other known
mangrove-conversion influences, such as decreased C sequestration
rate, burial efficiency, and export to ocean
16,18
, nor increases in
normally-low methanogenesis in some disturbed soils
16,27
.
In addition to direct losses of forest cover, land-use activities
will also impact mangrove responses to sea-level rise
14,15
. Man-
groves have been remarkably persistent through rapid sea-level rises
(5–15 mm yr
1
) during the late Quaternary Period (0–18,000 yr bp)
because of (1) landward migration, and (2) autogenic changes
in soil-surface elevation through below-ground organic matter
production and/or sedimentation
15
. Under current climate trends,
sea level is projected to rise 18–79 cm from 1999–2099 (higher
if ice-sheet melting continues accelerating)
8,30
, implying a period-
averaged rate of 1.8–7.9 mm yr
1
, notwithstanding local varia-
tions and temporal nonlinearities. Although this rate is not unprece-
dented, it is unclear yet whether mangroves are currently keeping
pace with sea levels
14,15
. Anthropogenic influences could constrain
future resilience to sea-level rise through coastal developments
that impede inland migration (for example, roads, infrastructure),
upland land uses that alter sediment and water inputs (for example,
dams, land clearing), and mangrove degradation that reduces
below-ground productivity
14
. This synergy of land use and climate
change impacts presents additional uncertainties for the fate and
management of coastal C stores.
Critical uncertainties remain before estimates of mangrove C
storage and land-use emissions can be improved. Among these are
geographic variations in soil depth, a key but unknown parameter
in most regions
5,21
. Similarly, empirical data on land-use change
impacts on soil C is strongly lacking, especially for deep layers
(but see refs 26–28). Quantitative estimates are also needed of
the relative area occupied by estuarine/delta and oceanic/fringe
mangroves, which is not addressed in most analyses of mangrove
area
4,6
. Because these two systems store below-ground C differently,
improved spatial data will greatly refine estimates of global C storage
and emissions owing to disturbance.
Our data show that discussion of the key role of tropical wetland
forests in climate change could be broadened significantly to include
mangroves. Southeast Asian peatlands are currently being advanced
as an essential component of climate change mitigation strategies
such as REDD+ (refs 7,13), and mangroves share many of the
same relevant characteristics: deep organic-rich soils, exceptionally
high C storage, and extensive deforestation/degradation resulting in
potentially large greenhouse gas emissions. The well-known ecosys-
tem services and geographic distribution of mangroves
1–4
suggest
these mitigation strategies could be effective in providing ancillary
benefits as well as potential REDD+ opportunities in many tropical
countries. Because land use in mangroves affects not only standing
stocks but also ecosystem response to sea-level rise, maintaining
these C stores will require both in situ mitigation (for example,
reducing conversion rates) as well as facilitating adaptation to
rising seas. The latter challenge is largely unique to management
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© 2011 Macmillan Publishers Limited. All rights reserved.
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NATURE GEOSCIENCE DOI: 10.1038/NGEO1123
0 10 35 60 85 110 135
Distance from seaward edge (m)
0 10 35 60 85 110 135
Distance from seaward edge (m)
Organic C content (%)
0
0
1
2
10 20
Depth (m)
0 10 20 0 10 20 0 10 20 0 10 20 0 10 20
Estuarine Oceanic
Bulk density (g cm
¬3
)
0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6
Estuarine/oceanic combined
Soil depth (m)
Estuarine (88% >3 m)
Oceanic
0
1
2
Depth (m)
Soil depth (m)
3
2
1
0
a
b
c
Figure 4 | Soil properties determining below-ground carbon storage in
Indo-Pacific mangroves. a, Soil C concentration was greater in oceanic
(mean = 14.6%) versus estuarine (mean = 7.9%) sites (P = 0.001), and
decreased with depth (P < 0.0001; effect stronger in oceanic sites).
Change in C concentration with seaward distance was biologically
insignificant. b, Soil bulk density did not differ significantly with setting
(P = 0.79); hence one line is shown combining both settings. Bulk density
increased with depth (P < 0.0001) but not seaward distance (P = 0.20),
and a distance*depth interaction term was not significant (P = 0.47). c, Soil
depth increased with distance from the seaward edge in oceanic stands
(FDA result: P = 0.002, 95% CI for rate-of-change = 21–65 cm increase
per 100 m distance).
of coastal forests, calling for watershed-scale approaches, such
as landscape buffers for accommodating inland migration where
possible, maintenance of critical upstream sediment inputs, and
addressing degradation of mangrove productivity from pollution
and other exogenous impacts
14,15
.
Methods
We sampled 25 mangrove sites (n = 10 estuarine, n = 15 oceanic) across the
Indo-Pacific (8
S–22
N, 90
–163
E) using a transect starting from, and running
perpendicular to, the seaward edge. To maximize scope and representativeness,
we stratified the sample across a broad range of stand conditions—including
small-stature stands and shallow soils (<4 m canopy height, <10 cm mean tree
diameter, <0.5 m soil depth) to large-stature stands and deep soils (>15 m canopy
height, >20 cm mean tree diameter, soil depth >3 m) (Supplementary Table S1).
These structural characteristics of forest stature and soil depth are primary
determinants of C storage, probably more so than environmental gradients or
geographic variation per se. Specific transect starts were determined randomly
a priori from aerial imagery, notwithstanding constraints of access and land
ownership. Within six circular sample plots spaced at 25-m intervals along each
transect, we measured standing tree and down wood (dead wood on forest floor)
biomass using standard biometric techniques (stem surveys, planar intercept
transects), then applying region-specific or common allometric equations and
C:biomass conversions for both above-ground and below-ground biomass. We
measured soil depths at three systematic locations in each plot using a graduated
aluminium probe (inference limit 3 m). We extracted a soil core from each plot
using a 6.4-cm open-face peat auger to minimize sample disturbance/compaction,
systematically divided the soil profile into depth intervals, and collected subsamples
from each interval. Subsamples were dried to constant mass and weighed for
bulk density determination, then analysed for C concentration using the dry
combustion method (induction furnace). Standard error in total ecosystem C
storage was computed by propagating standard errors of component pools. For
estuarine and oceanic sites separately, we analysed changes in soil depth and C
pools with distance from the seaward edge using functional data analysis (site-level
regressions for rate-of-change with distance, followed by a one-sample parametric
test on all rates-of-change for strength of positive or negative relationship). We
analysed spatial variations in soil C concentration and bulk density using linear
mixed-effects regression models, assessing fixed effects of depth, distance from
the seaward edge, and geomorphic setting, with a random effect of site to account
for within-site dependence. Ranges for global C storage and emission rates were
obtained using 5th percentile, mean, or 95th percentile estimates from this study
(which accounts for the possibility that biomass and soil C pools differ globally
from our mean values—higher or lower), with an adjusted soil C density based
on a recent global analysis
16
, combined with recently published low to high
estimates of global mangrove area and deforestation rate
1,4,6
. See full Methods in
Supplementary Information.
Received 30 September 2010; accepted 23 February 2011;
published online 3 April 2011
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Acknowledgements
We thank our many international partners and field personnel for assistance with
logistics and data collection: Kosrae Island Resource Management Authority; Yap
State Forestry; Orangutan Foundation International; Indonesian Directorate General
for Forest Protection and Nature Conservation; University of Manado and Bogor
Agricultural University, Indonesia; Bangladesh Forest Department; and KPSKSA
(Cilacap, Indonesia). We thank K. Gerow for statistical assistance, and R. Mackenzie,
C. Kryss and J. Bonham for assistance compiling site data. Funding was provided by
USDA Forest Service International Programs and the Australian Agency for International
Development (AusAID).
Author contributions
D.C.D. co-designed the study, collected field data, performed data analyses, and led the
writing of the paper. J.B.K. conceived and co-designed the study, and contributed to data
collection and writing. D.M. co-conceived the study, arranged for and contributed to data
collection, and contributed to writing. S.K. contributed to data collection, data analysis,
and writing. M.S. collected field data and contributed to writing. M.K. co-conceived the
study and contributed to writing.
Additional information
The authors declare no competing financial interests. Supplementary information
accompanies this paper on www.nature.com/naturegeoscience. Reprints and permissions
information is available online at http://npg.nature.com/reprintsandpermissions.
Correspondence and requests for materials should be addressed to D.C.D.
NATURE GEOSCIENCE | VOL 4 | MAY 2011 | www.nature.com/naturegeoscience 297
© 2011 Macmillan Publishers Limited. All rights reserved.
... propriedades físicas e químicas do solo, fatores ambientais e fatores biológicos como a produção de serapilheira e suas taxas de decomposição e a vegetação (REEF et al., 2010;THOMSON, 2010;KIM et al., 2012;FIEDLER et al., 2015). As emissões globais da degradação dos manguezais são até 0,12 pentagramas de carbono por ano, isso equivale a quase 10% das emissões globais associadas às florestas tropicais, embora ocupem 1% da área terrestre das florestas tropicais (DONATO et al., 2011). ...
... Os benefícios do manguezal se convertem em fonte econômica de subsistência proporcionando o bem-estar da sociedade (VO et al., 2012), conforme comprovado por Singh et al. (2010) (DONATO et al., 2011). Este ecossistema é reconhecido como potencial sumidouro de carbono e a chave para o sequestro de carbono da biomassa e do solo (ADAME et al., 2013;ALONGI, 2014). ...
Thesis
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This interdisciplinary research aims at investigating the seasonal and economic dimensions of the mangrove forest, in relation to the capture, storage and carbon emissions, from spatial variation of floristic, physical-chemical, biological and climatic variables for the period of 2016 and 2017 in the Eastern Amazon. The study area is located at the Experimental Site of UFRA / UFPA in the village of Cuiarana, Salinópolis-PA. The floristic inventory method consisted of transects and plots, with DBH measures ≥ 2.5cm, monthly precipitation data generated by the CMORPH technique and the tide of the Salinopólis Fundeadouro. The stock of organic carbon, CO2 emissions and physicochemical and biological variables were measured through seasonal sampling in nine 20x20m plots in three mangrove strata. Socioeconomic data are based on the combination of carbon dioxide fluxes measured by a micrometereological tower installed in the study area and interviews with residents of Cuiarana Village. Spatially, the main results show that for the three mangrove strata the dominance of Rhizophora mangle (L) was observed, with the highest values of phytosociological indices. The species Avicennia germinans (L.) Stearn presented a higher positive correlation (0.72) with organic carbon during the rainy season. The largest stocks and emissions of organic carbon in the soil occurred in the adult mangrove in the rainy season when compared to the young / dwarf and intermediate strata. In the socioeconomic context, the villagers identified nine mangrove properties of which the main ones are the consumption and the sale of the crab in the less rainy season. However, services for carbon capture and storage in the soil presented higher income in the rainy season. The incomes estimated by mangrove goods and services were R $ 92,660.50 per hectare per year.
... This ecosystem is also considered an ecosystem with complex trophic dynamics and is an area with high diversity (Medina-Contreras et al., 2020). Moreover, the mangrove ecosystem is the habitat of various coastal biota (Onrizal et al., 2020), fisheries production (Donato et al., 2011), and the production of coastal fisheries can be maintained by the existence of the mangrove ecosystem (Manson et al., 2005). In addition, fauna in the mangrove area can influence the structure of the vegetation which in turn will have an impact on the function of the mangrove ecosystem (Cannicci et al., 2008). ...
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Mangrove is an important ecosystem in coastal areas because it is the basis for the formation of food webs and has direct and indirect impacts on aquatic and terrestrial ecosystems. This research aims to determine the community structure of mangrove vegetation on the coast of Lubuk Damar, Seruway, Aceh Tamiang. The study was conducted in August 2017. The method used a quadratic transect that was pulled straight from the coastline to the mainland. The results found 10 species of mangrove consisting of A. alba, B. parviflora, B. sexangula, S. alba, R. apiculata, Acrostichum aureum, Aegiceras floridum, Excoecaria agallocha, X. granatum, and Acanthus ilicifolius. Mangrove species with the highest percentage are in the A. floridum species. Important value index the tree phase in the range of 4.75 to 117.91. Lubuk Damar mangrove vegetation is in the damaged category. However, the number of saplings and seedlings was found to have a high density so the ecosystem has the potential to regenerate naturally. How to cite (CSE Style 8 th Edition): Darmarini AS, Wardiatno Y, Prartono T, Soewardi K, Samosir AM, Zainuri M. 2022. Mangrove community structure in Lubuk Damar Coast, Seruway, Aceh Tamiang. JPSL 12(1): 72-81. http://dx.
... Donato et al. 2011) uncertainties in the stores of [carbon in] seagrass meadows.. ...
Preprint
Conservation biology emerged as a crisis discipline in the 20th century amongst an increasing awareness of pollution and habitat loss. Since the early 2000s, societal and monetary benefits of nature were added to the narrative for biodiversity conservation. Using text mining, we show that authors now favour an ecosystem-services over a crisis framing in scientific publications on coastal habitats. This may signal a shift in conservation science from a crisis to a services discipline despite continuing habitat loss. We discuss whether authors should more critically assess what conservation narrative they deploy and what consequences this may have for conservation action.
... Salah satu perannya adalah dapat mengakumulasikan bahan organik yang terendapkan oleh lapisan sedimen, bahan organik ini berupa karbon dan komponen lainnya dalam jumlah yang besar (Alongi 2008;Sanders 2010). Dibandingkan dengan tipe hutan lainnya meliputi hutan pada bagian bumi utara atau boreal, temprete dan hutan tropis , jumlah karbon yang dapat disimpan oleh hutan mangrove tiga kali lebih besar, dengan lebih dari 60% total karbon tersimpan dibawah tanah (Donato et al. 2011). Penelitian yang dilakukan oleh Murdiyarso et al. (2009) menunjukkan bahwa jumlah karbon yang dapat disimpan oleh ekosistem mangrove berkisar antara 863 -1073 MgC/Ha dengan rata-rata 968 MgC/ha. ...
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Jakarta is one of the provinces in Indonesia that experienced high population and economic growth from the last three decades with 10.3 million population and 0.94% per year population growth. Jakarta Bay experienced land cover change due to mangroves deforestation followed by land reclamation. Mangroves is an ecosystem that has a role to protect coastal zone from erosion and sea level rise. This ecosystem is capable to trap large amount of sediments, hence, build land. High population growth in Jakarta is followed by a bigger demand on freshwater which 64% of it comes from groundwater extraction. Over extraction of groundwater can trigger a hydro-geological disaster called land subsidence. Land cover analysis is done by using maximum likelihood algorithm, mapping of land subsidence is done by krigging interpolation, and the estimation model of land subsidence is done by Principal Component Regression. Mangrove in Jakarta Bay is deforested with 11,6 ha per year with the biggest drive is fishpond conversion (R2=0,5361, p=0,00043) and the expansion of build up area (R2=0,40973 p=0,0023). Mangrove with 508.83 ha (33.53%) is converted to fish pond and 146.07 ha (9.63%) is converted to build up area on 1995-2015. Land subsidence rate in Jakarta vary from 2-11 cm per year on 1998-2014. Western part of North Jakarta and Northern part of West Jakarta suffer from the biggest land subsidence. PCR analysis shows that the estimation of land subsidence based on groundwater availability can be determine as LS= -0.184Qcis -0.37Qcis + 0.171CH + 0.21Vol + 0.56Mang with coefficient of determination of 0.9. It means land subsidence increases when the discharge of Ciliwung and Cisadane decreases. On the other hand the land subsidence decreases when the ground water extraction, precipitation, andmangrove deforestation decreases.
... Mangrove's carbon sequestration is considered the best among other vegetations. Mangrove forests can absorb carbon four times more effectively than tropical forests because 75-95% of carbon is stored in the dead roots of one tree [4]. Indonesia's mangrove forest is the largest in the world [5]. ...
Conference Paper
Full-text available
Mangroves store significant carbon content that, when managed properly, will contribute to combating the climate crisis. Despite having the largest mangrove forest, Indonesia’s mangrove annual damage rate turns out to be the highest globally, one of the most significant factors is extensive plastic waste exposure, exacerbated by mangroves’ deforestation for conversion into agricultural land. Many efforts initiated by the government and other stakeholders have been targeting mangrove rehabilitation and plastic waste abatement. Labor-intensive and time-consuming ground checking have been the main source of information to determine priority areas for mangrove rehabilitation so far. This study aims to introduce a more effective and efficient identification of priority areas for rehabilitation. The study utilizes vulnerability index by optimizing remote sensing satellite data modeling. The study covers all mangroves in Indonesia, and for the purpose of this study, four mangrove vulnerability classes are formed to help categorize the severity of the damage. The classes are formed through integration, scoring, and classifying plant health, water turbidity, land temperature, plant carbon sequestration capability, and plastic waste distribution in Indonesian coastal area data. The modeling demonstrates its ability to distinguish the classes through machine learning. This study identifies that 65.74% of Indonesia’s coastal mangroves are highly exposed to plastic waste. Bali and Surabaya are two of the most severely damaged areas. This study, along with further analysis of socio-cultural, economic, and development priorities, will enable decision-makers to prioritize and mobilize necessary resources to rehabilitate the mangroves guided by a suitable mangrove management regime for each class.
... Mangroves help in the protection of seagrasses, coral reefs, and shrimp by collecting riverine runoff sediments (Primavera 1998;Valiela and Cole 2002;Duke and Larkum 2008, p. 156). They are an important component of "coastal blue carbon" as they store and sequester large amounts of carbon (Donato et al. 2011;Lee et al. 2014;Alongi 2015;Estrada and Soares 2017;Kelleway et al. 2017;Rogers et al. 2019). Current studies suggest that mangroves sequester higher carbon than the mature tropical rain forests and most of it is stored below ground, suggesting their important roles in combating climate change posed by global warming (Francisco et al. 2018;Sanderman et al. 2018; National Oceanic and Atmospheric Administration 2020). ...
Chapter
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Mangroves are globally recognized for their ecological, economic, social, and cultural importance. They provide a variety of goods and services to humanity. Mangroves are a group of trees and shrubs sheltered in the intertidal zones of tropical, subtropical, and warm temperate regions of the planet. They are adapted to a wide range of environmental conditions such as salinity, waterlogging, and inundation. They also are one of the most productive and biodiverse ecosystems on earth as they support the existence of a large number of organisms. Despite multiple goods and ecological services they deliver, mangrove ecosystems are one of the most vulnerable ecosystems because of several threats such as overexploitation, conversion, and encroachment of mangrove habitats for agricultural and settlement purposes, a decline in freshwater and silt deposition, heavy metal pollution, global warming, and sea level rise. This chapter provides important recent developments in the mangrove distribution, species diversity, diverse goods and services that they provide, threats to their survival, policies and global initiatives for their conservation, and challenges associated with conservation and restoration programs.
... The second hypothesis was therefore unsupported by these results as the spatial distribution of stocks was variable within both vegetation types. Significant variability in the distribution of blue carbon soil stocks have been consistently observed across different geomorphic settings, vegetation structure, soil type and soil depth (Chmura et al. 2003;Donato et al. 2011;Kauffman et al. 2011;Livesley and Andrusiak 2012;Saintilan et al. 2013;Adame et al. 2015;Kelleway et al. 2016a;Owers et al. 2016a;Hayes et al. 2017;Ewers Lewis et al. 2018;Owers et al. 2020). The only difference between our vegetation types within each of our study sites was at the broad scale; i.e. mangrove vs tidal marsh and soils were only sampled to the top 10 cm. ...
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The mangroves along the Mozambique coastline represent 2.3% of the world’s total man- 15 grove area. Theyare fundamental ecosystem services providers, namely as soft infrastructures for 16 mitigation and adaptation to extreme weather events and urban floods. In the context of Maputo, 17 these ecosystems are currently under threat, through ongoing land-use changes (short-term) and 18 sea-level rise (SLR) (mid-term) events. The study presents a methodology to map mangrove poten- 19 tial areas according to their ecological land suitability (MELS) in Maputo by applying a GIS -based 20 integrated model that uses a set of bio-physical criteria. Mapping the existent and potential MELS 21 areas, currently and facing a SLR scenario shows possibilities for integrating mangroves within an 22 urban green infrastructure whilst contributing to mangrove conservation, using MELS as an assess- 23 ment tool within the scope of coastal climate change adaptation
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Mangroves are the most blue-carbon rich coastal wetlands contributing to the reduction of atmospheric CO2 through photosynthesis (sequestration) and high soil organic carbon (C) storage. Globally, mangroves are increasingly impacted by human and natural disturbances under climate warming, including pervasive pulsing tropical cyclones. However, there is limited information assessing cyclone’s functional role in regulating wetlands carbon cycling from annual to decadal scales. Here we show how cyclones with a wide range of integrated kinetic energy (IKE) impact C fluxes in the Everglades, a neotropical region with high cyclone landing frequency. Using long-term mangrove Net Primary Productivity (Litterfall, NPPL) data (2001–2018), we estimated cyclone-induced litterfall particulate organic C (litter-POC) export from mangroves to estuarine waters. Our analysis revealed that this lateral litter-POC flux (71–205 g C m⁻² year⁻¹)—currently unaccounted in global C budgets—is similar to C burial rates (69–157 g C m⁻² year⁻¹) and dissolved inorganic carbon (DIC, 61–229 g C m⁻² year⁻¹) export. We proposed a statistical model (PULITER) between IKE-based pulse index and NPPL to determine cyclone’s impact on mangrove role as C sink or source. Including the cyclone’s functional role in regulating mangrove C fluxes is critical to developing local and regional climate change mitigation plans.
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Present study focuses on the carbon sequestration potential of five dominant mangrove species (Avicenia marina, Avicenia officinalis, Excoecaria agallocha, Rhizophora mucronata and Xylocarpous granatum) in Bhitarkanika and Mahanadi mangrove ecosystem. Water and soil parameters were sampled and analyzed for 10 selected stations along with aboveground biomass (AGB) and aboveground C (AGC) values. AGB value in the study area ranged from 15.00 ± 2.12 to 70.09 ± 6.68 tha −1 for A. marina, 26.13 ± 3.19 tha −1 to 616.94 ± 50.15 tha −1 for A. officinalis, 3.56 ± 0.96 tha −1 to 98.66 ± 5.24 tha −1 for E. agallocha, 7.06 ± 2.21 tha −1 to 224.41 ± 21.20 tha −1 for R. mucronata, and 0.64 ± 0.21 tha −1 to 6.25 ± 1.52 tha −1 for X. grana-tum, respectively. AGC value ranged from 7.63 ± 1.08 to 35.65 ± 2.63 tha −1 for A. marina, 1.73 ± 0.01 tha −1 to 280.83 ± 21.29 tha −1 for A. officinalis, 1.64 ± 0.41 tha −1 to 44.95 ± 2.53 tha −1 for E. agallocha, 3.44 ± 1.45 tha −1 to 114.05 ± 10.29 tha −1 for R. mucronata and 0.31 ± 0.10 tha −1 to 3.25 ± 0.31 tha −1 for X. granatum, respectively. The average SOC values in tha −1 varied from 3.52 ± 0.12 to 7.71 ± 0.45. The total carbon (AGC + SOC) calculated for the study area varied from 55.20 ± 7.90 to 330.41 ± 111.97 tha −1 with a mean total carbon of 124.11 ± 30.14 which is equivalent to 455.47 ± 110.56 tons of CO 2. Considering the total area of Bhitarkanika and Mahanadi mangrove ecosystem (672 + 141,589) to be 142,261 km 2 , the mean CO 2 e be 455.47 ± 110.56 tones, it is approx. 64,795,617.67 ≅ 64.80 TgC that were absorbed from the atmosphere, thus reducing the amount of carbon dioxide from the atmosphere.
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Mangrove ecosystems are threatened by climate change. We review the state of knowledge of mangrove vulnerability and responses to predicted climate change and consider adaptation options. Based on available evidence, of all the climate change outcomes, relative sea-level rise may be the greatest threat to mangroves. Most mangrove sediment surface elevations are not keeping pace with sea-level rise, although longer term studies from a larger number of regions are needed. Rising sea-level will have the greatest impact on mangroves experiencing net lowering in sediment elevation, where there is limited area for landward migration. The Pacific Islands mangroves have been demonstrated to be at high risk of substantial reductions. There is less certainty over other climate change outcomes and mangrove responses. More research is needed on assessment methods and standard indicators of change in response to effects from climate change, while regional monitoring networks are needed to observe these responses to enable educated adaptation. Adaptation measures can offset anticipated mangrove losses and improve resistance and resilience to climate change. Coastal planning can adapt to facilitate mangrove migration with sea-level rise. Management of activities within the catchment that affect long-term trends in the mangrove sediment elevation, better management of other stressors on mangroves, rehabilitation of degraded mangrove areas, and increases in systems of strategically designed protected area networks that include mangroves and functionally linked ecosystems through representation, replication and refugia, are additional adaptation options.
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Mangroves, the only woody halophytes living at the confluence of land and sea, have been heavily used traditionally for food, timber, fuel and medicine, and presently occupy about 181 000 km2 of tropical and subtropical coastline. Over the past 50 years, approximately one-third of the world's mangrove forests have been lost, but most data show very variable loss rates and there is considerable margin of error in most estimates. Mangroves are a valuable ecological and economic resource, being important nursery grounds and breeding sites for birds, fish, crustaceans, shellfish, reptiles and mammals; a renewable source of wood; accumulation sites for sediment, contaminants, carbon and nutrients; and offer protection against coastal erosion. The destruction of mangroves is usually positively related to human population density. Major reasons for destruction are urban development, aquaculture, mining and overexploitation for timber, fish, crustaceans and shellfish. Over the next 25 years, unrestricted clear felling, aquaculture, and overexploitation of fisheries will be the greatest threats, with lesser problems being alteration of hydrology, pollution and global warming. Loss of biodiversity is, and will continue to be, a severe problem as even pristine mangroves are species-poor compared with other tropical ecosystems. The future is not entirely bleak. The number of rehabilitation and restoration projects is increasing worldwide with some countries showing increases in mangrove area. The intensity of coastal aquaculture appears to have levelled off in some parts of the world. Some commercial projects and economic models indicate that mangroves can be used as a sustainable resource, especially for wood. The brightest note is that the rate of population growth is projected to slow during the next 50 years, with a gradual decline thereafter to the end of the century. Mangrove forests will continue to be exploited at current rates to 2025, unless they are seen as a valuable resource to be managed on a sustainable basis. After 2025, the future of mangroves will depend on technological and ecological advances in multi-species silviculture, genetics, and forestry modelling, but the greatest hope for their future is for a reduction in human population growth.
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Nearly 50% of terrigenous materials delivered to the world's oceans are delivered through just twenty-one major river systems. These river-dominated coastal margins (including estuarine and shelf ecosystems) are thus important both to the regional enhancement of productivity and to the global flux of C that is observed in land-margin ecosystems. The tropical regions of the biosphere are the most biogeochemically active coastal regions and represent potentially important sinks of C in the biosphere. Rates of net primary productivity and biomass accumulation depend on a combination of global factors such as latitude and local factors such as hydrology. The global storage of C in mangrove biomass is estimated at 4.03 Pg C; and 70% of this C occurs in coastal margins from 0 to 10 latitude. The average rate of wood production is 12.08 Mg ha–1 yr–1, which is equivalent to a global estimate of 0.16 Pg C/yr stored in mangrove biomass. Together with carbon accumulation in mangrove sediments (0.02 Pg C/yr), the net ecosystem production in mangroves is about 0.18 Pg C/yr. Global estimates of export from coastal wetlands is about 0.08 Pg C/yr compared to input of 0.36 Pg C/yr from rivers to coastal ecosystems. Total allochthonous input of 0.44 Pg C/yr is lower than in situ production of 6.65 Pg C/yr. The trophic condition of coastal ecosystems depends on the fate of this total supply of 7.09 Pg C/yr as either contributing to system respiration, or becoming permanently stored in sediments. Accumulation of carbon in coastal sediments is only 0.41 Pg C/yr; about 6% of the total input. The NEP of coastal wetlands also contribute to the C sink of coastal margins, but the source of this C is part of the terrestrial C exchange with the atmosphere. Accumulation of C in wood and sediments of coastal wetlands is 0.205 Pg C/yr, half the estimate for sequestering of C in coastal sediments. Burial of C in shelf sediments is probably underestimated, particularly in tropical river-dominated coastal margins. Better estimates of these two C sinks in the tropics, coastal wetlands and shelf sediments, is needed to better understand the contribution of coastal ecosystems to the global carbon budget.
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The coastal zone has changed profoundly during the 20th century and, as a result, society is becoming increasingly vulnerable to the impact of sea-level rise and variability. This demands improved understanding to facilitate appropriate planning to minimise potential losses. With this in mind, the World Climate Research Programme organised a workshop (held in June 2006) to document current understanding and to identify research and observations required to reduce current uncertainties associated with sea-level rise and variability. While sea levels have varied by over 120m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sea-level rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3mmyear−1. The major contributions to 20th and 21st century sea-level rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea-level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated. A suite of ongoing satellite and in situ observational activities need to be sustained and new activities supported. To the extent that we are able to sustain these observations, research programmes utilising the resulting data should be able to significantly improve our understanding and narrow projections of future sea-level rise and variability.
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Aboveground and belowground root biomasses (Babove and Broot) were measured for young, isolated Rhizophorastylosa on Iriomote Island, Japan. The relationship between these two parameters was significant and given as the equation, Broot(g dry weight) = 0.394 Babove(g dry weight) – 485 (r = 0.986). Multiple regression analyses also revealed good correlation between diameter and biomass of prop roots (Dprop and Bprop) and between prop root and root biomasses. Consequently, root biomass could be estimated from the measurements of diameter and biomass of prop roots using the multiple regression equation, Broot(g dry weight) = 80.0 Dprop(cm) + 0.86 Bprop (g dry weight) – 251. The relationship between DBH (diameter at breast height) and prop root biomass was also adequately described using an allometric equation.In Hinchinbrook Channel, Australia, redox potential (measured as Eh) and organic carbon stocks in the top 5cm of mangrove sediments were measured along a 600m transect from the frequently inundated, Rhizophora dominated zone on the creek edge, towards higher grounds, where Ceriops spp. became increasingly dominant. Eh values were about –60mV near the creek edge and increased to 260mV on higher grounds. Organic carbon stocks showed an opposite trend to Eh, with the values decreasing from about 360tCha–1 to 160tCha–1. At 18 sites, representing six different habitats, organic carbon stocks were also measured along with the DBH of mangrove trees. DBH was converted into aboveground biomass and then into root biomass using the equations obtained in the study on Iriomote Island. The average organic carbon stocks in the top 50 cm of sediments, aboveground biomass and root biomass were 296tCha–1, 123 tCha–1 and 52 tCha–1, respectively, and accounted for 64%, 25% and 11% of the total organic carbon stock.
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Accurate inventory of tropical peatland is important in order to (a) determine the magnitude of the carbon pool; (b) estimate the scale of transfers of peat-derived greenhouse gases to the atmosphere resulting from land use change; and (c) support carbon emissions reduction policies. We review available information on tropical peatland area and thickness and calculate peat volume and carbon content in order to determine their best estimates and ranges of variation. Our best estimate of tropical peatland area is 441 025 km 2 ($11% of global peatland area) of which 247 778 km 2 (56%) is in Southeast Asia. We estimate the volume of tropical peat to be 1758 Gm 3 ($ 18–25% of global peat volume) with 1359 Gm 3 in Southeast Asia (77% of all tropical peat). This new assessment reveals a larger tropical peatland carbon pool than previous estimates, with a best estimate of 88.6 Gt (range 81.7–91.9 Gt) equal to 15–19% of the global peat carbon pool. Of this, 68.5 Gt (77%) is in Southeast Asia, equal to 11–14% of global peat carbon. A single country, Indonesia, has the largest share of tropical peat carbon (57.4 Gt, 65%), followed by Malaysia (9.1 Gt, 10%). These data are used to provide revised estimates for Indonesian and Malaysian forest soil carbon pools of 77 and 15 Gt, respectively, and total forest carbon pools (biomass plus soil) of 97 and 19 Gt. Peat carbon contributes 60% to the total forest soil carbon pool in Malaysia and 74% in Indonesia. These results emphasize the prominent global and regional roles played by the tropical peat carbon pool and the importance of including this pool in national and regional assessments of terrestrial carbon stocks and the prediction of peat-derived greenhouse gas emissions.
Article
Aim Our scientific understanding of the extent and distribution of mangrove forests of the world is inadequate. The available global mangrove databases, compiled using disparate geospatial data sources and national statistics, need to be improved. Here, we mapped the status and distributions of global mangroves using recently available Global Land Survey (GLS) data and the Landsat archive. Methods We interpreted approximately 1000 Landsat scenes using hybrid supervised and unsupervised digital image classification techniques. Each image was normalized for variation in solar angle and earth–sun distance by converting the digital number values to the top-of-the-atmosphere reflectance. Ground truth data and existing maps and databases were used to select training samples and also for iterative labelling. Results were validated using existing GIS data and the published literature to map ‘true mangroves’. Results The total area of mangroves in the year 2000 was 137,760 km2 in 118 countries and territories in the tropical and subtropical regions of the world. Approximately 75% of world's mangroves are found in just 15 countries, and only 6.9% are protected under the existing protected areas network (IUCN I-IV). Our study confirms earlier findings that the biogeographic distribution of mangroves is generally confined to the tropical and subtropical regions and the largest percentage of mangroves is found between 5° N and 5° S latitude. Main conclusions We report that the remaining area of mangrove forest in the world is less than previously thought. Our estimate is 12.3% smaller than the most recent estimate by the Food and Agriculture Organization (FAO) of the United Nations. We present the most comprehensive, globally consistent and highest resolution (30 m) global mangrove database ever created. We developed and used better mapping techniques and data sources and mapped mangroves with better spatial and thematic details than previous studies.